drivers/hwmon/pmbus/zl6100.c

   1 /*
   2  * Hardware monitoring driver for ZL6100 and compatibles
   3  *
   4  * Copyright (c) 2011 Ericsson AB.
   5  * Copyright (c) 2012 Guenter Roeck
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/bitops.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/err.h>
  27 #include <linux/slab.h>
  28 #include <linux/i2c.h>
  29 #include <linux/ktime.h>
  30 #include <linux/delay.h>
  31 #include "pmbus.h"
  32
  33 enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105,
  34              zl9101, zl9117 };
  35
  36 struct zl6100_data {
  37         int id;
  38         ktime_t access;         /* chip access time */
  39         int delay;              /* Delay between chip accesses in uS */
  40         struct pmbus_driver_info info;
  41 };
  42
  43 #define to_zl6100_data(x)  container_of(x, struct zl6100_data, info)
  44
  45 #define ZL6100_MFR_CONFIG               0xd0
  46 #define ZL6100_DEVICE_ID                0xe4
  47
  48 #define ZL6100_MFR_XTEMP_ENABLE         BIT(7)
  49
  50 #define MFR_VMON_OV_FAULT_LIMIT         0xf5
  51 #define MFR_VMON_UV_FAULT_LIMIT         0xf6
  52 #define MFR_READ_VMON                   0xf7
  53
  54 #define VMON_UV_WARNING                 BIT(5)
  55 #define VMON_OV_WARNING                 BIT(4)
  56 #define VMON_UV_FAULT                   BIT(1)
  57 #define VMON_OV_FAULT                   BIT(0)
  58
  59 #define ZL6100_WAIT_TIME                1000    /* uS   */
  60
  61 static ushort delay = ZL6100_WAIT_TIME;
  62 module_param(delay, ushort, 0644);
  63 MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
  64
  65 /* Convert linear sensor value to milli-units */
  66 static long zl6100_l2d(s16 l)
  67 {
  68         s16 exponent;
  69         s32 mantissa;
  70         long val;
  71
  72         exponent = l >> 11;
  73         mantissa = ((s16)((l & 0x7ff) << 5)) >> 5;
  74
  75         val = mantissa;
  76
  77         /* scale result to milli-units */
  78         val = val * 1000L;
  79
  80         if (exponent >= 0)
  81                 val <<= exponent;
  82         else
  83                 val >>= -exponent;
  84
  85         return val;
  86 }
  87
  88 #define MAX_MANTISSA    (1023 * 1000)
  89 #define MIN_MANTISSA    (511 * 1000)
  90
  91 static u16 zl6100_d2l(long val)
  92 {
  93         s16 exponent = 0, mantissa;
  94         bool negative = false;
  95
  96         /* simple case */
  97         if (val == 0)
  98                 return 0;
  99
 100         if (val < 0) {
 101                 negative = true;
 102                 val = -val;
 103         }
 104
 105         /* Reduce large mantissa until it fits into 10 bit */
 106         while (val >= MAX_MANTISSA && exponent < 15) {
 107                 exponent++;
 108                 val >>= 1;
 109         }
 110         /* Increase small mantissa to improve precision */
 111         while (val < MIN_MANTISSA && exponent > -15) {
 112                 exponent--;
 113                 val <<= 1;
 114         }
 115
 116         /* Convert mantissa from milli-units to units */
 117         mantissa = DIV_ROUND_CLOSEST(val, 1000);
 118
 119         /* Ensure that resulting number is within range */
 120         if (mantissa > 0x3ff)
 121                 mantissa = 0x3ff;
 122
 123         /* restore sign */
 124         if (negative)
 125                 mantissa = -mantissa;
 126
 127         /* Convert to 5 bit exponent, 11 bit mantissa */
 128         return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
 129 }
 130
 131 /* Some chips need a delay between accesses */
 132 static inline void zl6100_wait(const struct zl6100_data *data)
 133 {
 134         if (data->delay) {
 135                 s64 delta = ktime_us_delta(ktime_get(), data->access);
 136                 if (delta < data->delay)
 137                         udelay(data->delay - delta);
 138         }
 139 }
 140
 141 static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
 142 {
 143         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 144         struct zl6100_data *data = to_zl6100_data(info);
 145         int ret, vreg;
 146
 147         if (page > 0)
 148                 return -ENXIO;
 149
 150         if (data->id == zl2005) {
 151                 /*
 152                  * Limit register detection is not reliable on ZL2005.
 153                  * Make sure registers are not erroneously detected.
 154                  */
 155                 switch (reg) {
 156                 case PMBUS_VOUT_OV_WARN_LIMIT:
 157                 case PMBUS_VOUT_UV_WARN_LIMIT:
 158                 case PMBUS_IOUT_OC_WARN_LIMIT:
 159                         return -ENXIO;
 160                 }
 161         }
 162
 163         switch (reg) {
 164         case PMBUS_VIRT_READ_VMON:
 165                 vreg = MFR_READ_VMON;
 166                 break;
 167         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 168         case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 169                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 170                 break;
 171         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 172         case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 173                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 174                 break;
 175         default:
 176                 if (reg >= PMBUS_VIRT_BASE)
 177                         return -ENXIO;
 178                 vreg = reg;
 179                 break;
 180         }
 181
 182         zl6100_wait(data);
 183         ret = pmbus_read_word_data(client, page, vreg);
 184         data->access = ktime_get();
 185         if (ret < 0)
 186                 return ret;
 187
 188         switch (reg) {
 189         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 190                 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 9, 10));
 191                 break;
 192         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 193                 ret = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(ret) * 11, 10));
 194                 break;
 195         }
 196
 197         return ret;
 198 }
 199
 200 static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
 201 {
 202         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 203         struct zl6100_data *data = to_zl6100_data(info);
 204         int ret, status;
 205
 206         if (page > 0)
 207                 return -ENXIO;
 208
 209         zl6100_wait(data);
 210
 211         switch (reg) {
 212         case PMBUS_VIRT_STATUS_VMON:
 213                 ret = pmbus_read_byte_data(client, 0,
 214                                            PMBUS_STATUS_MFR_SPECIFIC);
 215                 if (ret < 0)
 216                         break;
 217
 218                 status = 0;
 219                 if (ret & VMON_UV_WARNING)
 220                         status |= PB_VOLTAGE_UV_WARNING;
 221                 if (ret & VMON_OV_WARNING)
 222                         status |= PB_VOLTAGE_OV_WARNING;
 223                 if (ret & VMON_UV_FAULT)
 224                         status |= PB_VOLTAGE_UV_FAULT;
 225                 if (ret & VMON_OV_FAULT)
 226                         status |= PB_VOLTAGE_OV_FAULT;
 227                 ret = status;
 228                 break;
 229         default:
 230                 ret = pmbus_read_byte_data(client, page, reg);
 231                 break;
 232         }
 233         data->access = ktime_get();
 234
 235         return ret;
 236 }
 237
 238 static int zl6100_write_word_data(struct i2c_client *client, int page, int reg,
 239                                   u16 word)
 240 {
 241         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 242         struct zl6100_data *data = to_zl6100_data(info);
 243         int ret, vreg;
 244
 245         if (page > 0)
 246                 return -ENXIO;
 247
 248         switch (reg) {
 249         case PMBUS_VIRT_VMON_OV_WARN_LIMIT:
 250                 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 9));
 251                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 252                 pmbus_clear_cache(client);
 253                 break;
 254         case PMBUS_VIRT_VMON_OV_FAULT_LIMIT:
 255                 vreg = MFR_VMON_OV_FAULT_LIMIT;
 256                 pmbus_clear_cache(client);
 257                 break;
 258         case PMBUS_VIRT_VMON_UV_WARN_LIMIT:
 259                 word = zl6100_d2l(DIV_ROUND_CLOSEST(zl6100_l2d(word) * 10, 11));
 260                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 261                 pmbus_clear_cache(client);
 262                 break;
 263         case PMBUS_VIRT_VMON_UV_FAULT_LIMIT:
 264                 vreg = MFR_VMON_UV_FAULT_LIMIT;
 265                 pmbus_clear_cache(client);
 266                 break;
 267         default:
 268                 if (reg >= PMBUS_VIRT_BASE)
 269                         return -ENXIO;
 270                 vreg = reg;
 271         }
 272
 273         zl6100_wait(data);
 274         ret = pmbus_write_word_data(client, page, vreg, word);
 275         data->access = ktime_get();
 276
 277         return ret;
 278 }
 279
 280 static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
 281 {
 282         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 283         struct zl6100_data *data = to_zl6100_data(info);
 284         int ret;
 285
 286         if (page > 0)
 287                 return -ENXIO;
 288
 289         zl6100_wait(data);
 290         ret = pmbus_write_byte(client, page, value);
 291         data->access = ktime_get();
 292
 293         return ret;
 294 }
 295
 296 static const struct i2c_device_id zl6100_id[] = {
 297         {"bmr450", zl2005},
 298         {"bmr451", zl2005},
 299         {"bmr462", zl2008},
 300         {"bmr463", zl2008},
 301         {"bmr464", zl2008},
 302         {"zl2004", zl2004},
 303         {"zl2005", zl2005},
 304         {"zl2006", zl2006},
 305         {"zl2008", zl2008},
 306         {"zl2105", zl2105},
 307         {"zl2106", zl2106},
 308         {"zl6100", zl6100},
 309         {"zl6105", zl6105},
 310         {"zl9101", zl9101},
 311         {"zl9117", zl9117},
 312         { }
 313 };
 314 MODULE_DEVICE_TABLE(i2c, zl6100_id);
 315
 316 static int zl6100_probe(struct i2c_client *client,
 317                         const struct i2c_device_id *id)
 318 {
 319         int ret;
 320         struct zl6100_data *data;
 321         struct pmbus_driver_info *info;
 322         u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
 323         const struct i2c_device_id *mid;
 324
 325         if (!i2c_check_functionality(client->adapter,
 326                                      I2C_FUNC_SMBUS_READ_WORD_DATA
 327                                      | I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 328                 return -ENODEV;
 329
 330         ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
 331                                         device_id);
 332         if (ret < 0) {
 333                 dev_err(&client->dev, "Failed to read device ID\n");
 334                 return ret;
 335         }
 336         device_id[ret] = '\0';
 337         dev_info(&client->dev, "Device ID %s\n", device_id);
 338
 339         mid = NULL;
 340         for (mid = zl6100_id; mid->name[0]; mid++) {
 341                 if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
 342                         break;
 343         }
 344         if (!mid->name[0]) {
 345                 dev_err(&client->dev, "Unsupported device\n");
 346                 return -ENODEV;
 347         }
 348         if (id->driver_data != mid->driver_data)
 349                 dev_notice(&client->dev,
 350                            "Device mismatch: Configured %s, detected %s\n",
 351                            id->name, mid->name);
 352
 353         data = devm_kzalloc(&client->dev, sizeof(struct zl6100_data),
 354                             GFP_KERNEL);
 355         if (!data)
 356                 return -ENOMEM;
 357
 358         data->id = mid->driver_data;
 359
 360         /*
 361          * According to information from the chip vendor, all currently
 362          * supported chips are known to require a wait time between I2C
 363          * accesses.
 364          */
 365         data->delay = delay;
 366
 367         /*
 368          * Since there was a direct I2C device access above, wait before
 369          * accessing the chip again.
 370          */
 371         data->access = ktime_get();
 372         zl6100_wait(data);
 373
 374         info = &data->info;
 375
 376         info->pages = 1;
 377         info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 378           | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 379           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 380           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 381
 382         /*
 383          * ZL2004, ZL9101M, and ZL9117M support monitoring an extra voltage
 384          * (VMON for ZL2004, VDRV for ZL9101M and ZL9117M). Report it as vmon.
 385          */
 386         if (data->id == zl2004 || data->id == zl9101 || data->id == zl9117)
 387                 info->func[0] |= PMBUS_HAVE_VMON | PMBUS_HAVE_STATUS_VMON;
 388
 389         ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
 390         if (ret < 0)
 391                 return ret;
 392
 393         if (ret & ZL6100_MFR_XTEMP_ENABLE)
 394                 info->func[0] |= PMBUS_HAVE_TEMP2;
 395
 396         data->access = ktime_get();
 397         zl6100_wait(data);
 398
 399         info->read_word_data = zl6100_read_word_data;
 400         info->read_byte_data = zl6100_read_byte_data;
 401         info->write_word_data = zl6100_write_word_data;
 402         info->write_byte = zl6100_write_byte;
 403
 404         return pmbus_do_probe(client, mid, info);
 405 }
 406
 407 static struct i2c_driver zl6100_driver = {
 408         .driver = {
 409                    .name = "zl6100",
 410                    },
 411         .probe = zl6100_probe,
 412         .remove = pmbus_do_remove,
 413         .id_table = zl6100_id,
 414 };
 415
 416 module_i2c_driver(zl6100_driver);
 417
 418 MODULE_AUTHOR("Guenter Roeck");
 419 MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
 420 MODULE_LICENSE("GPL");